Barbara A. Bekins, PhD
I study biodegradation of groundwater contaminants. Presently I serve as research coordinator of a team studying a 1979 crude oil spill at the USGS study site near Bemidji, Minnesota. Studies at the site include the fate and bioeffects of oxyhdrocarbons formed during natural attenuation, controls on degradation rates, and use of biogenic heat to estimate degradation
EDUCATION
University of California, Santa Cruz, Ph.D., 1993, Hydrogeology
San Jose State University, M.S., 1988, Mathematics
University of California, Los Angeles, B.A., 1975, Mathematics
EXPERIENCE
1990-present: Research Hydrologist, U.S. Geological Survey, Water Resources Division
2006-2008 Instructor, Stanford University, Solute Transport in Groundwater
1988-1993: Researcher and Instructor, University of California, Santa Cruz.
1979-1987: Computer Specialist, U. S. Geological Survey, Seismology Branch.
Project chief, system administrator and UNIX consultant for computer facilities monitoring earthquakes in real time.
1977-1978: Research Assistant, Stanford University Geophysics Department.
1976-1977: Mathematics Lab Director, Canada Community College.
1975-1976: Scientific Programmer, SRI International.
HONORS
Member, National Academy of Engineering, 2020
AGU Fellow, 2019
GSA Fellow, 2005
GSA Hydrogeology Division Birdsall-Dreiss Lecturer, 2003-2004
U.S. Geological Survey Meritorious Service Award, 2004
JOI/USSAC Distinguished Lecturer, 2002-2003
ARCS Foundation Fellowship, 1989-1990
University of California Regents’ Fellowship, 1988-1989
B.A. Summa Cum Laude, Phi Beta Kappa
INTERNATIONAL OCEAN DISCOVERY PROGRAM PARTICIPATION
Exp. 366, Mariana Serpentine Mud Volcanoes, 12/2016-2/2017, Downhole Tools and Phys. Props.
Science Planning Committee, 2004-2007.
Leg 201, Peru Deep Biosphere, 1/2002-4/2002, Downhole Tools and Phys. Props.
U.S. Science Advisory Committee, 2000-2003.
Science Steering and Evaluation Panel, Earth's Environment, 1997-2000.
Leg 171A, Logging While Drilling, 12/1996-1/1997, Hydrologist.
Sedimentary and Geochemical Processes Panel, 1994-1996.
COMMITTEES
AGU Program Committee, 2013-2016
AGU Groundwater Technical Committee, Chair 2009-2010
National Research Council Panel on Intrinsic Remediation, 1997-2000.
JOURNAL EDITORIAL BOARDS
Groundwater Monitoring and Remediation 2021-present.
Geofluids, 2007-2017.
Hydrogeology Journal, 1997-2000.
Ground Water, 1998-2003.
Geology, 1995-1998.
Science and Products
A critical evaluation of crustal dehydration as the cause of an overpressured and weak San Andreas Fault
Response to commentary on observed methanogenic biodegradation progressions
Limited occurrence of denitrification in four shallow aquifers in agricultural areas of the United States
Nitrogen fluxes through unsaturated zones in five agricultural settings across the United States
Dissolution of biogenic ooze over basement edifices in the equatorial Pacific with implications for hydrothermal ventilation of the oceanic crust
Forensic fingerprinting of oil-spill hydrocarbons in a methanogenic environment-Mandan, ND and Bemidji, MN
Data report: Permeabilities of eastern equatorial Pacific and Peru margin sediments
An evaluation of factors influencing pore pressure in accretionary complexes: Implications for taper angle and wedge mechanics
Evaluation of unsaturated-zone solute-transport models for studies of agricultural chemicals
Progression of methanogenic degradation of crude oil in the subsurface
Use of dissolved and vapor‐phase gases to investigate methanogenic degradation of petroleum hydrocarbon contamination in the subsurface
Percolation and transport in a sandy soil under a natural hydraulic gradient
Science and Products
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Filter Total Items: 88
A critical evaluation of crustal dehydration as the cause of an overpressured and weak San Andreas Fault
Many plate boundary faults, including the San Andreas Fault, appear to slip at unexpectedly low shear stress. One long-standing explanation for a "weak" San Andreas Fault is that fluid release by dehydration reactions during regional metamorphism generates elevated fluid pressures that are localized within the fault, reducing the effective normal stress. We evaluate this hypothesis by calculatingAuthorsP.M. Fulton, D.M. Saffer, B.A. BekinsResponse to commentary on observed methanogenic biodegradation progressions
[No abstract available]AuthorsF. D. Hostettler, B.A. Bekins, C.E. Rostad, W.N. HerkelrathLimited occurrence of denitrification in four shallow aquifers in agricultural areas of the United States
The ability of natural attenuation to mitigate agricultural nitrate contamination in recharging aquifers was investigated in four important agricultural settings in the United States. The study used laboratory analyses, field measurements, and flow and transport modeling for monitoring well transects (0.5 to 2.5 km in length) in the San Joaquin watershed, California, the Elkhorn watershed, NebraskAuthorsC.T. Green, L.J. Puckett, J.K. Böhlke, B.A. Bekins, S.P. Phillips, L. J. Kauffman, J. M. Denver, H.M. JohnsonNitrogen fluxes through unsaturated zones in five agricultural settings across the United States
The main physical and chemical controls on nitrogen (N) fluxes between the root zone and the water table were determined for agricultural sites in California, Indiana, Maryland, Nebraska, and Washington from 2004 to 2005. Sites included irrigated and nonirrigated fields; soil textures ranging from clay to sand; crops including corn, soybeans, almonds, and pasture; and unsaturated zone thicknessesAuthorsC.T. Green, L.H. Fisher, B.A. BekinsDissolution of biogenic ooze over basement edifices in the equatorial Pacific with implications for hydrothermal ventilation of the oceanic crust
Recent observations indicate that curious closed depressions in carbonate sediments overlying basement edifices are widespread in the equatorial Pacific. A possible mechanism for their creation is dissolution by fluids exiting basement vents from off-axis hydrothermal flow. Quantitative analysis based on the retrograde solubility of calcium carbonate and cooling of basement fluids during ascent prAuthorsB.A. Bekins, A.J. Spivack, E.E. Davis, L. A. MayerForensic fingerprinting of oil-spill hydrocarbons in a methanogenic environment-Mandan, ND and Bemidji, MN
In recent decades forensic fingerprinting of oil-spill hydrocarbons has emerged as an important tool for correlating oils and for evaluating their source and character. Two long-term hydrocarbon spills, an off-road diesel spill (Mandan, ND) and a crude oil spill (Bemidji, MN) experiencing methanogenic biodegradation were previously shown to be undergoing an unexpected progression of homologous n-aAuthorsFrances D. Hostettler, Y. Wang, Y. Huang, W. Cao, Barbara A. Bekins, Colleen E. Rostad, C. F. Kulpa, Andrew E. LaursenData report: Permeabilities of eastern equatorial Pacific and Peru margin sediments
Constant-flow permeability tests were conducted on core samples from Ocean Drilling Program Leg 201 from the eastern equatorial Pacific and the Peru margin. Eighteen whole-round core samples from Sites 1225, 1226, 1227, 1230, and 1231 were tested for vertical permeabilities. Sites 1225, 1226, and 1231 represent sediments of the open ocean, whereas Sites 1227 and 1230 represent sediments of the oceAuthorsKusali Gamage, Barbara A. Bekins, Elizabeth ScreatonAn evaluation of factors influencing pore pressure in accretionary complexes: Implications for taper angle and wedge mechanics
At many subduction zones, accretionary complexes form as sediment is off-scraped from the subducting plate. Mechanical models that treat accretionary complexes as critically tapered wedges of sediment demonstrate that pore pressure controls their taper angle by modifying basal and internal shear strength. Here, we combine a numerical model of groundwater flow with critical taper theory to quantifyAuthorsD.M. Saffer, B.A. BekinsEvaluation of unsaturated-zone solute-transport models for studies of agricultural chemicals
Seven unsaturated-zone solute-transport models were tested with two data sets to select models for use by the Agricultural Chemical Team of the U.S. Geological Survey's National Water-Quality Assessment Program. The data sets were from a bromide tracer test near Merced, California, and an atrazine study in the White River Basin, Indiana. In this study the models are designated either as complex orAuthorsBernard T. Nolan, E. Randall Bayless, Christopher T. Green, Sheena Garg, Frank D. Voss, David C. Lampe, Jack E. Barbash, Paul D. Capel, Barbara A. BekinsProgression of methanogenic degradation of crude oil in the subsurface
Our results show that subsurface crude-oil degradation rates at a long-term research site were strongly influenced by small-scale variations in hydrologic conditions. The site is a shallow glacial outwash aquifer located near Bemidji in northern Minnesota that became contaminated when oil spilled from a broken pipeline in August 1979. In the study area, separate-phase oil forms a subsurface oil boAuthorsB.A. Bekins, F. D. Hostettler, W.N. Herkelrath, G. N. Delin, E. Warren, H.I. EssaidUse of dissolved and vapor‐phase gases to investigate methanogenic degradation of petroleum hydrocarbon contamination in the subsurface
At many sites contaminated with petroleum hydrocarbons, methanogenesis is a significant degradation pathway. Techniques to estimate CH4 production, consumption, and transport processes are needed to understand the geochemical system, provide a complete carbon mass balance, and quantify the hydrocarbon degradation rate. Dissolved and vapor‐phase gas data collected at a petroleum hydrocarbon contamiAuthorsRichard T. Amos, K. Ulrich Mayer, Barbara A. Bekins, Geoffrey N. Delin, Randi L. WilliamsPercolation and transport in a sandy soil under a natural hydraulic gradient
Unsaturated flow and transport under a natural hydraulic gradient in a Mediterranean climate were investigated with a field tracer experiment combined with laboratory analyses and numerical modeling. Bromide was applied to the surface of a sandy soil during the dry season. During the subsequent rainy season, repeated sediment sampling tracked the movement of bromide through the profile. Analysis oAuthorsChristopher T. Green, David A. Stonestrom, Barbara A. Bekins, Katherine C. Akstin, Marjorie S. Schulz